Field of the Invention
The present invention relates to a piping connection structure for connecting a resin tube and a pipe body.
Description of the Related Art
In recent years, it has been proposed to constitute part or all of the function of a connector with a resin tube in a piping connection portion in order to reduce size and costs of that portion. For example, PTLs 1 to 5 describe structures in which a seal member is disposed between a diameter-expanded portion of a resin tube and a pipe body by processing an end portion of the resin tube beforehand so as to expand its diameter. These documents also mention that the pipe body is restricted from coming off by processing the end portion of the resin tube beforehand and having this portion of the resin tube caught by an annular projection of the pipe body.